Water systems in Wisconsin exceed allowable lead levels more often than in most states across the country, according to data from the U.S. Environmental Protection Agency.

From 2012 to 2015, 81 Wisconsin water systems tested above the EPA action level at least once, meaning more than 10 percent of the locations tested during a given period exceeded the EPA limit of 15 parts per billion. Twelve systems topped the action level in two or more testing periods.

On a per-capita basis, that is the 12th-highest number of failed systems in the nation.

Several water systems have had particularly persistent problems, led by the tiny one serving THINK Academy in the Wisconsin Rapids School District. The system failed lead tests once in 2013, twice in 2014 and once last year.

The first letter alerting parents was sent in November 2013, two months after the first failed tests. The school said no drinking fountains had tested above the EPA limit, but it still asked parents to send bottled water for their children to drink at school.

Wisconsin Rapids Superintendent Colleen Dickmann said the district has since replaced faucets and shutoffs that contained +lead — which were believed to be the cause of the high levels — and is also in the process of installing a water treatment system.

“We have been working closely with the (Wisconsin Department of Natural Resources) as they have been guiding us through the process since first detection to be certain we are compliance with regulations,” Dickmann wrote.

THINK Academy, previously known as Rudolph Elementary School, is one of four state water systems listed in enforcement status with the DNR, said agency spokesman George Althoff. All four are in compliance with agreements they’ve made about how to address the problem.

The three other water systems under enforcement are in Genoa City, Mosinee and the Fox Lake Correctional Institution in Dodge County. All three are required to do public education and treat the water supply with phosphates to keep lead from leaching into tap water. Genoa and Mosinee must also remove lead service lines and issue consumer notices, while Fox Lake is required to abandon and rehabilitate certain wells.

THINK Academy was one of two Wisconsin water systems to top allowable lead levels in more than two testing periods since 2012. The other is Lake Mills, about 50 west of Milwaukee in Jefferson County.

DNR records show 10 percent of the water system’s tests topped 80 ppb from 2013-15, and 20 percent were over the 15 ppb threshold. City Public Works Director Paul Hermanson said the lead leaching into drinking water is in the pipes of individual homes, “not in the water supply.”

Each water system tests only a fraction of its homes, which are presumed to be representative of the system as a whole. Lake Mills tested 40 homes in older areas with a higher likelihood of lead plumbing. High tests have resulted, but not in predictable ways.

“You could go to the same house every month for a year and get dramatically different tests whether or not they’ve done anything to alleviate the situation. It’s a moving target,” Hermanson said, noting there is no apparent solution for the city aside from having affected residents run the water several minutes before using it.

Older homes such as those prevalent in Lake Mills are more likely to have lead piping inside and lead connections to city water mains. Many municipalities replace the city portion of those connecting lines if they’re doing projects in the area, but others have made more concerted efforts.

Madison has spent more than $15 million since 2001 to replace all 8,000 lead lines between the water main and the home, including both the city- and resident-owned sections. The city now knows of only eight remaining lead service lines on the home side, and none on the city side of the house-main connection, said Amy Barrilleaux, spokeswoman for Madison Water Utility.

Appleton and Wisconsin Rapids report lead service lines comprise only 1 percent of their systems.

In Green Bay, the water utility is developing a plan to replace about 1,700 remaining lead service lines, representing about 5 percent of the system.

Milwaukee has about 70,000 city-owned lead service lines, representing about 44 percent of its customers. Manitowoc is close behind at 43 percent. Sheboygan and Wausau are at 38 and 37 percent, respectively.

A high percentage of lead pipes doesn’t necessarily mean lead in the water, however, as systems have typically added chemicals to keep the lead from seeping into the water. In Sheboygan, water utility Superintendent Joe Trueblood noted lead levels at 90 percent of locations tested were at or below one-fifth of the EPA limit.

Eric Litke is an investigative reporter for USA TODAY NETWORK-Wisconsin. Reach him at 920-453-5119, elitke@gannett.com or on Twitter@ericlitke.

LEAD IN YOUR WATER: AN INVESTIGATION
Lead in your water | A USA TODAY Network Investigation | 5:14

Across the country almost two thousand drinking water systems have failed lead testing since 2012. A USA TODAY Network investigation found harmful levels of lead in homes, schools, and other public buildings.
USA TODAY NETWORK

LEAD IN YOUR WATER: AN INVESTIGATION
Video: Unearthing lead lines | 1:18

Elmira Water Board maintenance crews work to replace lead water pipes under West Water Street in the Town of Elmira on March 9. The board has proactively worked over the past seven or eight years to replace the lead lines across the town and city.
KELLY GAMPEL / Staff Video

LEAD IN YOUR WATER: AN INVESTIGATION
Lead fixtures in Jackson water system | 3:32

Joints that run approximately every 20 feet along a large portion of Jackson's water system include lead. Clarion-Ledger reporter Anna Wolfe reached out to city officials for an explanation.
Anna Wolfe/The Clarion-Ledger